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  <a name="EN-US_TOPIC_0000002164828434"></a><a name="EN-US_TOPIC_0000002164828434"></a>
  <h1 class="topictitle1">Backup Fails Because the Number of Asynchronous I/O Requests in the Production Environment Reaches the Maximum</h1>
  <div>
   <div class="section">
    <h4 class="sectiontitle">Symptom</h4>
    <p>A backup job fails. You can view the description of the failed event on the job page, as shown in the following figure.</p>
    <p><span><img src="en-us_image_0000002200155097.png"></span></p>
   </div>
   <div class="section">
    <h4 class="sectiontitle">Possible Cause</h4>
    <p>The number of asynchronous I/O requests in the production environment reaches the maximum. As a result, the backup fails.</p>
   </div>
   <div class="section">
    <h4 class="sectiontitle">Procedure</h4>
    <ol>
     <li><span>Log in to the production environment and run the <strong>vi /etc/sysctl.conf</strong> command to check the value of <strong>fs.aio-max-nr</strong> in insert mode.</span></li>
     <li><span>Determine the cause of the problem according to the following scenarios:</span><p></p>
      <ul>
       <li>If the <strong>fs.aio-max-nr</strong> parameter is abnormal (less than the reference value or not found), reconfigure the parameter based on the reference value <strong>18446744073709551615</strong> of the parameter in <a href="https://help.sap.com/docs/SAP_HANA_PLATFORM/6b94445c94ae495c83a19646e7c3fd56/82e4575eec664846a9918e9ed1d90d41.html" target="_blank" rel="noopener noreferrer">Linux Kernel Parameters</a>, and then go to <a href="#EN-US_TOPIC_0000002164828434__li265812449712">3</a>.</li>
       <li>If the <strong>fs.aio-max-nr</strong> parameter exists and its value is normal (you can refer to the parameter value in <a href="https://help.sap.com/docs/SAP_HANA_PLATFORM/6b94445c94ae495c83a19646e7c3fd56/82e4575eec664846a9918e9ed1d90d41.html" target="_blank" rel="noopener noreferrer">Linux Kernel Parameters</a>), collect logs and contact Huawei technical support engineers.</li>
      </ul> <p></p></li>
     <li id="EN-US_TOPIC_0000002164828434__li265812449712"><a name="EN-US_TOPIC_0000002164828434__li265812449712"></a><a name="li265812449712"></a><span>Run the <strong>sysctl -p /etc/sysctl.conf</strong> command for the configuration to take effect. After the command is executed, perform the backup again.</span></li>
    </ol>
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     <strong>Parent topic:</strong> <a href="en-us_topic_0000002164828418.html">FAQs</a>
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